Chapter 5 Flashcards
Amniocentesis
A method of acquiring fetal cells for karyotyping that involves extracting fluid from the amniotic sac.
Anaphase
The stage of mitosis in which sister chromatids are pulled apart.
This is the stage of mitosis when karyokinesis occurs.
Oogenesis
production of an egg or ovum
Polyploidy
is the presence of extra sets of chromosomes in an organism.
Prophase
mitotic phase during which chromatin condenses so that chromosomes appear.
Tumor Suppressor Gene
Gene coding for a protein that ordinarily suppresses cell division; inactivity can lead to a tumor
Trisomy 21
One more chromosome than usual
Telophase
Daughter cells physically separate
Telomeres
the end of a chromosome; shortens with every round of replication and it helps determine the number of times a cell can divide
Synapsis
Pairing of homologous chromosomes during prophase 1of meiosis
Spindle Fibers
Microtubule strcture that brings about chromosomal movement during nuclear division
Spermatogonium
primitive male reproductive cells
Spermatogenesis
production of sperm in males by the process of meiosis and matration
Seminiferous Tubule
highly coiled duct within the male testes that produces and transport sperm
Telophase 1
The first stage of meiosis that follows anaphase 1
Polar bodies
nonfunctioning daughter cell, formed during oogenesis, that has little cytoplasm.
Oocyte
the female gamete, or egg, prior to fertilization.
P-53 gene
A gene that is thought to play a role in regulating cell death or apoptosis, in suppressing tumors, in regulating the cell cycle, and in stopping the cell from dividing when the DNA is damaged.